In communication devices, such as portable two-way radios, it is known to provide an externally accessible radio frequency (RF) accessory port for attaching remote antennas and other RF accessories. In one example, a radio has an RF port connected to the RF path of an integral antenna. An RF switch, internal to the radio, selectively switches the RF path from the integral antenna to the RF accessory port. Typically, the RF switch is automatically actuated when an accessory is connected to the RF accessory port. The prior art describes a variety of approaches for incorporating RF switches within a radio to support such functions.
One prior art approach is described in U.S. Pat. No. 5,278,570, issued to Jaramillo, et al., on Jan. 11, 1994, for a Combined Coaxial Connector and Radio Frequency Switch Assembly. In this approach, an antenna connector and RF switch assembly are integrated on a portable radio device. A switch, internal to the radio, is actuated when an external connector is attached to the housing. The switch is actuated by an external plunging mechanism that operates through an opening in the radio device housing. Another example is described in U.S. Pat. No. 5,365,027, issued to Marvet, et al., on Nov. 15, 1994, for a Slide Switch Assembly. Here, a switch assembly is surface mounted to a printed circuit board within a radio communication device. An associated external connector provides a port for attaching RF accessories. When an external accessory is connected to the connector, the accessory causes a plunger to be depressed thereby actuating the switch and rerouting RF signals from an antenna path to the accessory port. In both approaches, as typical in the art, the RF switch assembly is incorporated within the main body of the radio communication device. This design approach is used even though many radio users may not need an RF accessory port. As a result, unnecessary manufacturing costs are incurred which are ultimately borne by these users.
It is desirable to provide for the attachment of RF accessories to a radio when the need arises, and to provide for associated RF switching. However, the manufacturing expense and complexity associated with RF switches should be avoided unless needed by a particular user. Therefore, a new approach to the provision of RF switching to support external RF accessories is needed.